this suite of tools can be used to retrieve a local copy
from the FreeCAD wiki and then use it to generate qhelp
and pdf files. The downloading of the entire wiki is now
a huge operation, prone to network errors, so it has been
cut into 2 parts, one to retrieve a list of files to
download and another to actually download the files.

1) run "buildwikiindex.py" to build an index file containing
   a list of all the files to download

2) run "downloadwiki.py". If connection drops, run it again, 
   the already downloaded files will be skipped.

3) run "buildqhelp.py" to generate freecad.qhc and freecad.qch
   files

4) run "buildpdf.py" to generate freecad.pdf (wkhtmltopdf must be installed)

5) the qhelp files can be tested with "assistant -collectionFile freecad.qhc"